The effects of low-carbohydrate (LC) diets on body weight and cardiovascular risk are unclear, and previous studies have found varying results. Our aim was to conduct a meta-analysis of randomised controlled trials (RCT), assessing the effects of LC dietsv. low-fat (LF) diets on weight loss and risk factors of CVD. Studies were identified by searching MEDLINE, Embase and Cochrane Trials. Studies had to fulfil the following criteria: a RCT; the LC diet was defined in accordance with the Atkins diet, or carbohydrate intake of <20 % of total energy intake; twenty subjects or more per group; the subjects were previously healthy; and the dietary intervention had a duration of 6 months or longer. Results from individual studies were pooled as weighted mean difference (WMD) using a random effect model. In all, eleven RCT with 1369 participants met all the set eligibility criteria. Compared with participants on LF diets, participants on LC diets experienced a greater reduction in body weight (WMD –2·17 kg; 95 % CI –3·36, –0·99) and TAG (WMD –0·26 mmol/l; 95 % CI –0·37, –0·15), but a greater increase in HDL-cholesterol (WMD 0·14 mmol/l; 95 % CI 0·09, 0·19) and LDL-cholesterol (WMD 0·16 mmol/l; 95 % CI 0·003, 0·33). This meta-analysis demonstrates opposite change in two important cardiovascular risk factors on LC diets – greater weight loss and increased LDL-cholesterol. Our findings suggest that the beneficial changes of LC diets must be weighed against the possible detrimental effects of increased LDL-cholesterol.

Background: Although sun exposure is an established cause of cutaneous malignant melanoma, possible interactions with host factors remain incompletely understood. Here we report the first results from a large prospective cohort study of pigmentation factors and sun exposure in relation to melanoma risk. Methods: The Women’s Lifestyle and Health Cohort Study included 106 379 women from Norway and Sweden who were aged 30–50 years in 1991 or 1992 when they completed an extensive questionnaire on personal characteristics and exposures. Linkages to national registries ensured complete follow-up through December 31, 1999. Poisson regression models were used to estimate relative risks (RRs). All statistical tests were two-sided. Results: During an average follow-up of 8.1 years, 187 cases of melanoma were diagnosed. Risk of melanoma was statistically significantly associated with increasing body surface area (RR for ⩾1.79 m² versus ⩽1.61 m² = 1.60, 95% confidence interval [CI] = 1.03 to 2.48; P_trend = .02), number of large asymmetric nevi on the legs (RR for ⩾7 nevi versus 0 nevi = 5.29, 95% CI = 2.33 to 12.01; P_trend<.001), hair color (RR for red versus dark brown or black = 4.05, 95% CI = 2.11 to 7.76; P_trend<.001), sunburns per year at ages 10–19, 20–29, and 30–39 years (P_trend<.001, P_trend = .03, and P_trend = .05, respectively), and use of a device that emits artificial light (solarium) one or more times per month (P = .04). Conclusions: Our results confirm previous findings that hair color, number of nevi on the legs, and history of sunburn are risk factors for melanoma and suggest that use of a solarium is also associated with melanoma risk. Adolescence and early adulthood appear to be among the most sensitive age periods for the effects of sunburn and solarium use on melanoma risk. However, it may be too early to see the full effect of adult exposures in this cohort.

Background: The prevalence of metabolic syndrome (obesity, glucose intolerance, low serum high-density lipoprotein cholesterol [HDL-C], high serum triglycerides, hypertension) is high and increasing in parallel with an increasing breast cancer incidence worldwide. HDL-C represents an important aspect of the syndrome, yet its role in breast cancer is still undefined. Methods: In two population-based screening surveys during 1977–1983 and 1985–1987, serum HDL-C was assayed enzymatically among 38 823 Norwegian women aged 17–54 years at entry. Height, weight, blood pressure, serum lipids, fat and energy intake, physical activity, parity, oral contraceptive use, hormone therapy use, alcohol intake, and tobacco use were also assessed. We used Cox proportional hazards modeling to estimate the relative risk (RR) of breast cancer associated with serum HDL-C levels and to adjust for potential confounding variables. We performed stratified analyses to evaluate effect modification by body mass index (BMI) and menopausal status. All statistical tests were two-sided. Results: During a median follow-up of 17.2 years, we identified 708 cases of invasive breast cancer. In multivariable analysis, the risk of postmenopausal breast cancer was inversely related to quartile of HDL-C (P_trend = .02). Among women with HDL-C above 1.64 mmol/L (highest quartile) versus below 1.20 mmol/L (lowest quartile), the relative risk was 0.75 (95% confidence interval [CI] = 0.58 to 0.97). The HDL-C association was confined to women in the heavier subgroup (BMI ≥25 kg/m²), for whom the relative risk of postmenopausal breast cancer in those with HDL-C above 1.64 mmol/L versus below 1.20 mmol/L was 0.43 (95% CI = 0.28 to 0.67; P_trend<.001; P_interaction = .001). Conclusion: Low HDL-C, as part of the metabolic syndrome, is associated with increased postmenopausal breast cancer risk.